Embodiments of the disclosure relate to micro-electromechanical system (MEMS) microphones and methods of their construction. In particular, embodiments of the disclosure relate to constructions of a membrane of the MEMS microphone and overtravel stops that support said membrane.
Capacitive MEMS microphones measure sound pressure levels with a pressure-sensitive membrane. The membrane must be of sufficient mechanical strength to withstand various acoustic pressures without being destroyed. In addition to mechanical strength, the membrane must be sensitive to sensing small acoustic pressures. Sensitivity, natural frequency, and response characteristics are affected by the construction and shape of the membrane and the mounting of the membrane to the MEMS microphone die. Therefore, performance of the MEMS microphone is due, at least in part, to the membrane structure and mounting configurations of the membrane.